title: Chiral phosphoric acid catalyzed enantioselective synthesis of β-amino-α,α-difluoro carbonyl compounds.
abstract: A biphenol-based chiral phosphoric acid bearing a 9-anthryl group at each of the 3,3'-positions catalyzed the asymmetric Mannich-type reaction of N-Boc imine with difluoroenol silyl ethers in the presence of MS3A in THF to afford β-amino-α,α-difluoroketones in good yields and with excellent enantioselectivities. Optically pure 3,3-difluoroazetidin-2-one was readily synthesized from the Mannich-adduct.
authors.affiliation: Department of Chemistry, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Kashikura
authors.forename: Keiji
authors.initials: K
authors.lastname: Mori
authors.forename: Takahiko
authors.initials: T
authors.lastname: Akiyama
mesh_terms: D000588:Amines / Q000737:chemistry*; D002384:Catalysis; D017611:Fluorine Compounds / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010756:Phosphoric Acids / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000588:Amines; D017611:Fluorine Compounds; D010756:Phosphoric Acids; D012997:Solvents